The infamous “American Taliban” John Walker Lindh wrote a few letters to reporters and authors praising Afghan Taliban jihad and the Islamic State (ISIS/ISIL), prompting recipients of the correspondence to label him unrepentant as authorities released the jihadi into U.S. communities on Thursday.

“The Islamic State is clearly very sincere and serious about fulfilling the long-neglected religious obligation to establish a caliphate through armed struggle, which is the only correct method,” Lindh wrote to NBC News’ Los Angeles station KNBC from prison in a letter unveiled Wednesday.

NBC reveals:

Lindh expressed that sentiment — in response to a question from the station about whether ISIS represents Islam —after ISIS had beheaded Americans in well-publicized videos, including journalist James Foley in August 2014. It was his third of four letters in a series of correspondence with KNBC.

After initially expressing remorse about joining the Taliban, Lindh sounded a different tune to NBC, goading that he was proud “to take part in the Afghan jihad.”

The “American Taliban” has maintained correspondence with news outlets from prison, including Graeme Wood from the Atlantic.

“His more than 17 years in captivity seem, on the basis of this correspondence, to have converted Lindh from an al-Qaeda supporter to an Islamic State supporter,” Wood determined.

Lindh is expected to move to either Northern Virginia, right outside of the U.S. capital, or return to his hometown in Marin country located in San Francisco’s Bay Area.

“The chances that Marin County will someday have an unrepentant jihadist praying in its mosques, and soaking in its (woman-free) hot tubs, seem very high,” the Atlantic reports.

“He wanted martyrdom, and he said so,” Pelton indicated, referring to the “American Taliban.”

Pelton indicated:

Lindh seemed like a sociopath who had been working really hard to be with a group that was killing Americans and fellow Muslims. … Authorities certainly know about Lindh’s continuing radicalism—not least because they have read every word of my correspondence with him.

Lindh’s early release comes about three years before the end of his 20-year-jail stint, courtesy of a plea agreement.

Under the plea pact, prosecutors reportedly dropped nine of ten counts leveled against Lindh in 2002, including one for murder conspiracy. Lindh pled guilty to “disobeying an executive order outlawing support to the Taliban and for possessing a weapon in Afghanistan,” Fox News notes.

The Mercury News learned that Lindh’s release “comes a few years short of his 20-year sentence due to credits for good conduct and time served before his sentencing.”

Authorities released the “American Taliban” despite concerns from current and former U.S. officials that he remains a potential Islamic terrorist threat, NBC News learned, adding:

Underscoring those worries is Lindh’s 2015 handwritten letter from prison to NBC’s Los Angeles station KNBC —revealed for the first time Wednesday — in which he expressed support for ISIS, saying the terror group that beheaded Americans was “doing a spectacular job.”

Furthermore, documents obtained by Foreign Policy show that, as early 2017, the National Counterterrorism Center stressed that Lindh continued to “advocate for global jihad and write and translate violent extremist texts.”

Last March, he told a TV producer that he would “continue to spread violent extremism Islam upon his release,” according to Fox News.

Lindh’s correspondence with journalists and other comments he made in prison formed part of the basis of a 2016 U.S. intelligence document, produced by the National Counter Terrorism Center, saying that he “continued to advocate for global jihad and to write and translate violent extremist texts.”

Lindh has expressed interest in wanting to live in Northern Virginia, right outside the nations’ capital, his lawyer confirmed to the NBC affiliate in the Bay Area — KNTV.

“It is one of the most restrictive sets of conditions I’ve seen in a terrorism case, and it probably speaks to their concerns about him,” Seamus Hughes, a former U.S. intelligence official who studies extremism at George Washington University, told NBC News, adding:

The conditions of his supervised release last three years, after which Lindh will be clear of formal supervision. U.S. officials told NBC News the FBI is likely to keep a close eye on him. It’s unclear whether authorities would have a legal predicate to obtain a national security warrant to intercept his communications.

NBC News reached out to Lindh’s lawyer and a representative of his family for comments, but they declined.

In his letters to NBC 4 Los Angeles signed under a pseudonym, he said he was proud “to take part in the Afghan jihad.”

In a rare show of bipartisanship, Sens. Richard Shelby (R-AL) and Maggie Hassan (D-NH) wrote a letter to the Federal Bureau of Prisons last week expressing concern over the looming release of convicted American Taliban jihadi and other terrorists.

U.S. troops captured him in late 2001 soon after invading Afghanistan in response to 9/11.